1. Field of Invention
This invention relates to golf clubs, specifically an improved sole contour for wedge golf clubs providing improved utility for all short game play in the game of golf.
2. Prior Art
Gene Sarazen invented the bounce sole contour for the modern sand wedge club in the early 1930's—specifically for sand play (See FIG. 1). That same sole contour remains the standard for wedge clubs 70 years later following the turn of the millennium. The great problem with the Sarazen bounce sole contour is that it was designed exclusively for sand play—whereas, the modern game of golf has evolved into a far more demanding game with regard to short game shot-making situations. Golf equipment in general has changed greatly, and the golf courses where the modern game is played are more difficult—wedge clubs now need greater versatility.
The singular purpose for Sarazen's widely copied bounce sole contour for sand wedges is for playing sand bunker explosion shots—certainly less than 20% of all short game play. For ALL other short game situations (the great majority the modern golf player encounters) this bounce sole contour is problematic.
This same Sarazen-inspired bounce sole that is so helpful for sand shots creates a dangerously raised leading edge for the bottom of the club face (approximately 6 mm.) above the playing surface. This raised leading edge increases the difficulty associated with playing all other short game shots (besides bunker explosion shots), increases the skill and precision required for executing these shots, and greatly increases the risk of a poor outcome with a less than perfect shot attempt. This also creates limitations with regard to weight distribution in a sand wedge club head design.
This raised leading edge problem for sand wedges has not been ignored by the better golf equipment designers over the years. Attempts at lowering the leading edge for improved short game play have been many and varied. Some designers have tried adding a convex or cambered shape modification (extending face to back) to a basic Sarazen bounce sole. This had the effect of lowering the leading edge, but this also reduced the effective bounce angle for the rearward portion of the bounce sole. Other designers have simply reduced the width of the bounce sole to lower the leading edge—also compromising the sand play effectiveness of that golf club. Many of these designs are present in the current state of the art.
There have also been several reduced bounce angle cambered wide sole club head designs to appear in golf during the last 20 years—specifically intended to help the golfer that lacks the skill or knowledge of technique required to play bunker explosion shots. Reduced bounce angle cambered wide sole designs (FIG. 3) play acceptably from bunkers for explosion shots and play square-faced shots well enough, but they lack the essential versatility of opening the club face to add loft when needed to increase trajectory or ball spin rates. Opening the club face on these wide sole club designs will raise the leading edge to heights completely unplayable, thereby limiting these designs greatly in their versatility—the versatility needed by players of all skill levels for the broader range of shot-making situations encountered in the modern game of golf.
Koehler's dual bounce sole (U.S. Pat. No. 5,301,944 issued April 1994) lowered the leading edge with his two distinctly different bounce surfaces, but the bounce angle for his larger rearward surface was at the same time significantly decreased (see FIG. 4)—thereby reducing the playing effectiveness of this design for bunker explosion shots—Koehler just compromised the golf club's playing effectiveness for bunker explosions to obtain the needed utility of a lowered leading edge.
Braly's concave sole design (U.S. Pat. No. 3,810,631 issued May 1974) was another lowered leading edge improvement for a sand wedge. In this design, the inventor introduced an area of concavity to the sole of the golf club for providing bounce when needed for bunker play (see FIG. 5). The great problem with the Braly sole was two-fold. First, this sole design produced an excessively wide sole and thick club head, which was completely unplayable for open-faced playing situations. Secondly, with the effective bounce contour being derived from the concavity extending from the forward part of the sole toward the rear, the effective bounce angle was constantly changing. This design concavity provided an ineffective negative bounce angle in its most forward areas and gradually transitioned through a point of zero bounce to an area of maximum bounce angle at the most rearward edge—but it still provided only a minimal bounce angle even at that most rearward point. The effectiveness of this design for sand play was found in the increased surface area of the bounce surface provided instead of the steepness (or correctness) of the bounce angles.
Both Koehler and Braly offered the lowered leading edge improvement that was needed, but they compromised either bounce effectiveness for utility (Koehler), or they compromised utility for bounce effectiveness (Braly)—neither provided both.
Still other bounce sole designs from the prior art lacked the essential understanding that bunker explosion shots only comprised a small portion of the total demands of the short game, and they did little to lower the leading edge—unless they too reduced the bounce angles.